Valve-silencing mechanism



Dc. 16, 1930. C` .,CLED 1,785,523

I VALVE sLENcING MEcHANIsM Filed Sept. 2e. 192e /f/ if if /Z /0 77' l YPatented Dec. 176,A 1930 crirronnLivrcrinonoFk QUINCY, MASSACHUSETTSfvALvEp-sILE'NoInG:MECHANISMQy fi i 'Appneauq'n mea september 26,19218.VV spriiv-nalsqsyiiks.

A 10 lhenlthe rocker arm or othervalve-openingmember moves tolperrnit,the, valve tol close under rthe action 'of its spring, the arm mustYordinarily be adjusted to move clear of the valve stem when the valvecloses, in Vorder to valverin closingjhits its seatlwith the fullpressure of the val-ve spring on i it..` This causesconsiderable noiseand wear. When the rocker larm starts' itsValVe-Openinglmotion, it mustfirst take 4up theclearan'ce space A between itf'and the'endofgthegvalve stem before engaging` the stern'toy open the valve. This causes aclick between the arm and stem which adds to the noiseand wear. Accord-25 ing to the present invention I greatly reduce theenoise and wear onthe valve and itsassof ciated parts by means oi. asimple and eiectivedevice for resilientlyopposing the action Vof the valvefspringuntiltl'ievalveis'seated, fand, for maintaining the? valve f stem andVroclnerK-armf inV mutual Contact i atfall times.V Variousadvantageouseatures of construe-i: tion will `be apparent to.V oneskilled in theart from the description ofthe inventionwlrich follows,and i'`rom` the drawing; of which :`A

Figure lfisa perspectiveV view of an-element employed inthe mechanism. Al Figure-Zie a-side elevation ofthe same.4 :Figure 3 is a side elevationof a rocker bar formed for usewith the element shown'in Figure 1. *y p fv. r vFigure l is aside elevationipartly'broken away and'in section of apoppet valvewith valve opening mechanism and valve silencing mechanism.Y l, Figure 5 is a similar View showing therparts CTI in a differentyposition of operation. f i Figure 6 isa perspective view of a modi- 50.fied form of elementtor valve silencing` mechanism. v

13. The. spring maybe; as usual Va helical s allow the valve to-'seattightly.` Thus kthe `The .rockero bar v10' .ispro'videdwithfan `arm asmall clearance between'thexend ofthe arm.

{tactf is established ,betweenftheend of -the Inworder to i -inotionlmay :provide '1 an lintertting. tongue Figure 7 isa `flanged pintorusewith the elementvshown in 'F1'gure6. L

Figure 8 is a section of a rocker arm aclapt-z 4ed' to fcooperate fwitlrthe elements shownQin .Figures and'l';V y, jReieIring toV the'` drawingin. detail, rl() represents ayroker barwhichfis vadapted to.

rock on a shaft 11, inn orderfto open a poppet i i valve' 12";which .is.constantly lpressed;to? i .ward its closed positionfby'avalve spring '6coil underfcompression `between theinotor y casing `14C-and awasherl'whi'ch` secured adjacent to the end' of thel valve stem 16.

17, motion of which serves to` open thefvalvelehrte:permitira,.cioseimdepu1@ action of Y 'l "thespring Thevalve-opening motionof i the-.armml'may be producedas by ap'ush y Inorder to permit thevalve toseat tightly,

`and theend of thevalve stem must be allowed as otherwisegany wear onthe valve seat or the vcontacting face of the valve would resultinfaffailure'of the yalve'ftojclose tightly.

According :to Y Vthis vinvention a resilient con- Varm-17y andthe endofthe valve stem sothat the clickpusually incident-[to thei'meeting of ilfthe rockenarm-Land'thenvalvelstein is, thus avoided. To thisendairockable elementor shoe 19 maybe .p1'ovided,.` this shoe being carlyried byL the' rocker," arin y'17l and d held thereonagainstglongitudinal or lateralsliding motionhtheshoe beingfreeyhowever,to rock on the arm. c: l' 7 90 prevent relativel longitudinal 20- and'rgroove 21.r As shown on*k the drawing, the tongue is l:formedtransversely on the rockerv arm 17', the groove `21*beingformed in thee5 shoe 19..n If desired, l1owever.,'the.tonguemayy be formed on theshoeyandthe-groove in the arm. The shoe may be providedwithacurvedelongated portionQQ, this portion serving as a leverarniV which may befengaged by a suit- 10u Y whichis opposed to the shoe may be'recessedable leaf spring 23 which is `mounted on the rocker bar. The elongatedportion 22 may be provided with a pair of flanges or fins 24 which arearranged to engage thevsidefaces of the rocker arm 17 so asto preventrelative `lateral or transverse motion betweentheshoe 19 and the arm 17.The face of the arm as at 25 so that the shoe will normally pivot on asmall portionl f the face of the arm VV17 Which is adjacent toanedge26.The :spring 231nay be secured to the rocker bar as by a suitable" screw27 or by any other means `This spring, as shown inFigures 4 andr, is

preferably curved so as tocooperate with the curvature of theextension22 of the shoe 19 in such fa Way as toengage thelface of the .shoeselectively at dierent pointsalong the length of the extension 22according to the position Vofoperation of the valve opening andsilencing mechanism. ,When the `valve is closed as shown in Figure 4,the end ofthespring 23 -which is remote from its pointof support engagesthe shoe 19 at apoint well spaced .from Iboth ends thereof. AllVhen thevalve is openfthep'arts are as shown"in- Figure 5 wherein the spring 23isrepresented as pengaging the .shoeV 19 at a'lpoint near the end oftheshoe which is remote fromthe point of its Contact with the valvefsteni16. "In this position the intermediate `portion of the springrather thanvits free 'end engages' 'the shoe 19. `As this,` intermediatefportionl'is nearer to the pointof support' of the spring than is thefree end,"the springfthusoiers a jstiffer'resis'tance, the eifect ofthisresistance on the shoe beingmagnified by the factthat the lever arm 22which fulcrums on the surface adjacent to the edgej26V is effectivelylonger' when thevalve 12 is open, since the spring 23 in this caseengages the extension 22'near lthe end remote from the `fulcrum ratherthan at a point nearer the fulcrum as inFigure 4. The resultof thisconstruction is' to oppose an increasing "resistance to the rockingmotion of the shoefas thei valve Y12 opens. Thus when the rocker bar 10is rocked from its position, as .shown in Figure 4,`inv order to openthel valve 12, the ,'shoe19is pressed against the end of the valvevstemfl and, tends to rock onitsfulcrum in' opposition to the pres-sureof the spring 235011 its extension 22. Asv the rocker bar rocks further,an ,increasing pressure is thus'caused between the shoe 19 andthe stem16V by the virtualincrease of the lever arm 22ffrom v,the

i f fulcrum to the pointof conta'ctof the arm 22"with thegspring`23,until the tendency of the springto roclrthe shoe in one direction .isbalanced by the pressureagainst the valve stem 16-which tends to rockthe shoe in the vopposite direction. Thereupon, further rocking motionofthe rocker bar-1,0 serves to move the valve to its open position.A Whenl the valve returnslto its closed position, the' bal-V ,bpring 23.'

ance between the opposingirnoments on the shoe 19 lcaused by thepressure of the valve stem 16 at one end of thevshoe and the pressureofthe spring23 'near the other end of ythe shoe is maintainedV until thevalve reaches its seat, whereupon vthe shoe 19 rocks to reduce itspressure against the end of the valve stem when 'the arm is furtherwithdrawn and thus increasingly lto permit the -valve spring 15 to pressthe valve'12 firmly against its seat. :In this Waytheblow of the valve12 against its seat is minimized since at the in- Aorder to prevent sideslipping ofthespring withlreference to the extension l22,'.I may mountin the latter a pin 28 which may eX-, tend Vto` a,y suitable,perforation 29v inthe Figures 56 and i 8 .illustrate a 'modifiedeinventing relative longitudinal and lateral mo-V tion between the sliceand thefroclrer arm.

bodimentof they invention, different fmeansheilig employed in thisembodimentjforpre- According to' this embodimentr the rocker arm f8() is'providedwith a transverse recessl'near its end.' The shoe 32is likewiserecessed as at 33, the recesses 1,- 'being opposite each other so as toform ane'arly cylindrical perforation in which ,inayfbe mounted arpin 34having flanged ends '35'. :"Thebody ofthe pin 34, as shown, formsapivoton which the k'shoe may' roel; and 'prevents relative longitudinalmovement` between vthe'shoe and the 'rockerarrm the' flanged' vends 35serving to prevent lateral movement.A The'recesses 31, 331ma'y be shapedsomewhat asshown in Fig ure 8 to allow thefbody of thefpin 34aslight.`rolling 'motion as the s'hoef 32.-' rocks on the. armBO; This redufceswear on the pin 34 and j thefcontacting faces; The'action of the shoe 32is identical with the .action Aof the shoe 19. which has'beenlhereinbefore`described in de- Having thus described 'anembodiment'of this invention, it should be evident to those skilled-ignthe art thatvarious changes and ,modifications might,V "made thereinwithout departing from itsfspirrt orscope'as delined bvV they appendedclaims. *Y I claim:

l OO

"1. The' combination `with a valve, `a stein thereon, and avalveiclosing spring, of. a inem- Y oer movable toopen the valveAagainst 'the pressure ofthe spring` a stem-contacting ele- Ament,rockably'carried by said member and arranged to engage said stemadjacent to one "end of said element, and a spring secured to saidmember and engaging said element selectively at various points extendingfrom the central portion of the element tothe end remote from saidstem-engaging end, the point of contact between the element and tleelement-eno'aeines rino' de endinf on the nosies c n n a i tion ofoperation of said member and stem.

2; Valve-silencing mechanism comprising a rocker bar having an arm, avalve stem moval'Jle by therocking motionof said arnnand yielding meanscarried bysaid arm and` en-V Y gaging said stem, said yielding meansinclud# yielding means carried bysaid. arm and engagin g said stem, saidyielding means incl-uding a member having direct rocking contact withsaid arm, said stem being arrangedto bear en one end portion of saidmembergand a spring bearing on the opposite end portion 1 of said memberat a point about half-way between the ends of the member when the valveis closed, and at a point near the end of the member when thevalve isopen.`

4. The combination with a valve ll'iaving a stem andavalve-actuatingmember, of valve silencing mechanism comprising a.cooperating memberrroclrably carried by saidvalvey actuating memberandengaging said'stem, said members having a transverse tongue andgroove engagement whereby relative 'longitudinal motion between saidmembers is prevented, one of said members having1 lateral liangesengamngtheother said inemberto prevent relative transverse motionbetween said members, and aspring carried by said valve-actuating memberand engaging said cooperating member on its end portion remote fromv the'point of engagement with said stem.

5. The combination with a valve` a stem thereon,cand alvalve-closingspring, of a member movable to open the valve against thepressure of said'spring, a stem-contactfingelement rockably carried bysaid inember and arranged toengage said' stein adjazcent to one end ofsaid element, and a spring secured to said member and engaging saidAelement selectively at various pointsextendsignature..l

-a member having direct rocking contact with said arm andn having an endportion bear` ing directly on said stem and a spring bearingon theopposite end portion'of `said member selectively at various pointsaccording im 4. tothe position'of operation ofsaid member,

Vsaid arm and member havingiopposed faces adjacent to the stem-engagingend .of said member and mutually engageable to preventlongitudinalgslipof said member on said arm.v

l -`TQValve-silencing mechanisml comprising a rocker bar havingan arm,`la Vvalve stem lmovable by rocking motion of said arm, a

member having direct rocking Contact with saidarm` and havingy anendportion bearing directly on said stem', and a spring bear- 1 ing on theopposite kend portionof said Inemy ber, said armandmember having opposedfaces adjacent Vto the stem-engaging end of said member and mutuallyengageable to prevent longitudinal slip Vof saidmember on saidarm. '1f

l- 8. Valve silencing mechanism comprising a rocler'bar'having an arm,ya valve stem movable by rocking `motion of said arm, av

member having direct rocking contact with said arm and having an endportion bearing directly KVon said stem whereby pressure be-f tween saidstem andV memberytends torock the member onthe arm, and lpaspringbearing on said member and tendingto rock said member in opposition tosaid stem, said arm and member having opposed faces thereon mutuallyengageableto prevent longitudinal slip of said membe'ronsaid arm. i I

In testimony whereof .Ifhave alfi'iedimy cerimonia,i MeLEoD;

ing from the central portion ofthe element Y to the end remote from saidstem-engaging end, said member` and element havingr opposed facesthereon mutually engageable to ment and member.

prevent longitudinal slip between said ele? 6. Valve-silencing mechanismcomprising a rocker-bar having an arm, a valve stem movable by therocking motion of said arm',

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